i have a murrey riding mower 42910X92A 14.5 hp 42″.i have spent over 400.00 dollors and still the same.when they start it runs great i drive it around thier lot take it home it starts up i turn on the blade it cuts great.I take a bresk turn it of come out nothing not a sound. this last time i turned it on and of atlest 5 times, so i’am thinkimg it has to do with the blade on & off ?.But what help please.